U.S. Pat. No. 4,759,335 was issued 26 July 1988 in the names of P. W. Ragg, M. L. McKay and R. S. Brooks, and international patent application publication WO 86/00960 published 13 Feb. 1986 in the name of M. L. McKay, show embodiments of a injector that delivers a fuel-air charge directly into the combustion chamber of a two-stroke cycle engine. The injector has a valve that is opened by a solenoid to allow the fuel-air charge to be delivered into the combustion chamber, and that is closed against a seat by a spring to terminate delivery of the fuel-air charge.
Experience with injectors of that nature has revealed a tendency for the valve to bounce repeatedly onto and off its seat when the spring attempts to close the valve. As a result, the injector does not terminate delivery of the fuel-air charge as intended.